CN117810454A - Positive electrode material and preparation method and application thereof - Google Patents
Positive electrode material and preparation method and application thereof Download PDFInfo
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- CN117810454A CN117810454A CN202410233691.3A CN202410233691A CN117810454A CN 117810454 A CN117810454 A CN 117810454A CN 202410233691 A CN202410233691 A CN 202410233691A CN 117810454 A CN117810454 A CN 117810454A
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- 239000007774 positive electrode material Substances 0.000 title claims abstract description 129
- 238000002360 preparation method Methods 0.000 title abstract description 51
- 239000010410 layer Substances 0.000 claims abstract description 306
- 239000010416 ion conductor Substances 0.000 claims abstract description 109
- 230000007704 transition Effects 0.000 claims abstract description 106
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 97
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 96
- 229910052751 metal Inorganic materials 0.000 claims abstract description 85
- 239000002184 metal Substances 0.000 claims abstract description 84
- 239000002344 surface layer Substances 0.000 claims abstract description 22
- 229910012851 LiCoO 2 Inorganic materials 0.000 claims description 75
- 239000000843 powder Substances 0.000 claims description 75
- 239000002245 particle Substances 0.000 claims description 57
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 claims description 55
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 claims description 55
- 239000011029 spinel Substances 0.000 claims description 51
- 229910052596 spinel Inorganic materials 0.000 claims description 51
- 239000003792 electrolyte Substances 0.000 claims description 46
- 238000001354 calcination Methods 0.000 claims description 45
- 238000000034 method Methods 0.000 claims description 44
- 229910052744 lithium Inorganic materials 0.000 claims description 43
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 42
- 239000000203 mixture Substances 0.000 claims description 42
- 238000002156 mixing Methods 0.000 claims description 41
- 235000002639 sodium chloride Nutrition 0.000 claims description 36
- 239000012266 salt solution Substances 0.000 claims description 34
- 239000000243 solution Substances 0.000 claims description 34
- 238000001035 drying Methods 0.000 claims description 33
- 229910052782 aluminium Inorganic materials 0.000 claims description 27
- 239000011248 coating agent Substances 0.000 claims description 27
- 238000000576 coating method Methods 0.000 claims description 27
- 239000011780 sodium chloride Substances 0.000 claims description 27
- 238000003756 stirring Methods 0.000 claims description 27
- 239000002243 precursor Substances 0.000 claims description 26
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 25
- 239000002904 solvent Substances 0.000 claims description 18
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 16
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 16
- 239000000725 suspension Substances 0.000 claims description 14
- 238000006467 substitution reaction Methods 0.000 claims description 13
- 229910021645 metal ion Inorganic materials 0.000 claims description 12
- 229910000428 cobalt oxide Inorganic materials 0.000 claims description 11
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 claims description 11
- 238000010791 quenching Methods 0.000 claims description 11
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- 239000011777 magnesium Substances 0.000 claims description 8
- 229910052759 nickel Inorganic materials 0.000 claims description 8
- 239000010955 niobium Substances 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 229910052684 Cerium Inorganic materials 0.000 claims description 7
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 7
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 7
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 7
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 7
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000012535 impurity Substances 0.000 claims description 7
- 229910052741 iridium Inorganic materials 0.000 claims description 7
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 claims description 7
- 229910052746 lanthanum Inorganic materials 0.000 claims description 7
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 7
- 229910052749 magnesium Inorganic materials 0.000 claims description 7
- 229910052758 niobium Inorganic materials 0.000 claims description 7
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 7
- 229910052707 ruthenium Inorganic materials 0.000 claims description 7
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- 239000010703 silicon Substances 0.000 claims description 7
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- 229910052719 titanium Inorganic materials 0.000 claims description 7
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims description 7
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 6
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 6
- 229910052726 zirconium Inorganic materials 0.000 claims description 6
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- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
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- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 25
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- 238000005245 sintering Methods 0.000 description 25
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- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 23
- ZTILUDNICMILKJ-UHFFFAOYSA-N niobium(v) ethoxide Chemical compound CCO[Nb](OCC)(OCC)(OCC)OCC ZTILUDNICMILKJ-UHFFFAOYSA-N 0.000 description 21
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 20
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- 239000010405 anode material Substances 0.000 description 16
- 238000011065 in-situ storage Methods 0.000 description 16
- 229910000664 lithium aluminum titanium phosphates (LATP) Inorganic materials 0.000 description 16
- 239000011812 mixed powder Substances 0.000 description 14
- 230000005501 phase interface Effects 0.000 description 14
- 238000007086 side reaction Methods 0.000 description 14
- 150000002500 ions Chemical group 0.000 description 13
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 13
- 229910020599 Co 3 O 4 Inorganic materials 0.000 description 11
- 239000006256 anode slurry Substances 0.000 description 10
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- 229910032387 LiCoO2 Inorganic materials 0.000 description 4
- 239000011247 coating layer Substances 0.000 description 4
- 238000004891 communication Methods 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- 230000006872 improvement Effects 0.000 description 4
- WJZHMLNIAZSFDO-UHFFFAOYSA-N manganese zinc Chemical compound [Mn].[Zn] WJZHMLNIAZSFDO-UHFFFAOYSA-N 0.000 description 4
- 238000001000 micrograph Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 229910012305 LiPON Inorganic materials 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- CKFRRHLHAJZIIN-UHFFFAOYSA-N cobalt lithium Chemical compound [Li].[Co] CKFRRHLHAJZIIN-UHFFFAOYSA-N 0.000 description 3
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- 238000004146 energy storage Methods 0.000 description 3
- 238000000643 oven drying Methods 0.000 description 3
- 238000004448 titration Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 229910002651 NO3 Inorganic materials 0.000 description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 2
- KLARSDUHONHPRF-UHFFFAOYSA-N [Li].[Mn] Chemical compound [Li].[Mn] KLARSDUHONHPRF-UHFFFAOYSA-N 0.000 description 2
- 230000003190 augmentative effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000010406 cathode material Substances 0.000 description 2
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- 239000004973 liquid crystal related substance Substances 0.000 description 2
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000007773 negative electrode material Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
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- GPKIXZRJUHCCKX-UHFFFAOYSA-N 2-[(5-methyl-2-propan-2-ylphenoxy)methyl]oxirane Chemical compound CC(C)C1=CC=C(C)C=C1OCC1OC1 GPKIXZRJUHCCKX-UHFFFAOYSA-N 0.000 description 1
- 229910018871 CoO 2 Inorganic materials 0.000 description 1
- 229910021503 Cobalt(II) hydroxide Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910009178 Li1.3Al0.3Ti1.7(PO4)3 Inorganic materials 0.000 description 1
- 229910013733 LiCo Inorganic materials 0.000 description 1
- 229910013553 LiNO Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- OJIJEKBXJYRIBZ-UHFFFAOYSA-N cadmium nickel Chemical compound [Ni].[Cd] OJIJEKBXJYRIBZ-UHFFFAOYSA-N 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- ASKVAEGIVYSGNY-UHFFFAOYSA-L cobalt(ii) hydroxide Chemical compound [OH-].[OH-].[Co+2] ASKVAEGIVYSGNY-UHFFFAOYSA-L 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- YNQRWVCLAIUHHI-UHFFFAOYSA-L dilithium;oxalate Chemical compound [Li+].[Li+].[O-]C(=O)C([O-])=O YNQRWVCLAIUHHI-UHFFFAOYSA-L 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
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- -1 for example Substances 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 239000010442 halite Substances 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 230000037427 ion transport Effects 0.000 description 1
- 239000011244 liquid electrolyte Substances 0.000 description 1
- XIXADJRWDQXREU-UHFFFAOYSA-M lithium acetate Chemical compound [Li+].CC([O-])=O XIXADJRWDQXREU-UHFFFAOYSA-M 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 1
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 1
- 229910001947 lithium oxide Inorganic materials 0.000 description 1
- 230000003211 malignant effect Effects 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
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- 230000035484 reaction time Effects 0.000 description 1
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- 230000000284 resting effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- VSZWPYCFIRKVQL-UHFFFAOYSA-N selanylidenegallium;selenium Chemical compound [Se].[Se]=[Ga].[Se]=[Ga] VSZWPYCFIRKVQL-UHFFFAOYSA-N 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- BSWGGJHLVUUXTL-UHFFFAOYSA-N silver zinc Chemical compound [Zn].[Ag] BSWGGJHLVUUXTL-UHFFFAOYSA-N 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Abstract
The embodiment of the application provides a positive electrode material, a preparation method and application thereof, and relates to the technical field of lithium ion battery materials, wherein a body of the positive electrode material is of a first layered structure, and the first layered structure consists of a first element, a second element and a third element; the transition layer is distributed along the direction deviating from the body, the transition layer at least comprises a second layered structure, the second layered structure is connected with the body, the second layered structure is composed of a first element, a second element and a third element, or the second layered structure is composed of the first element, the second element, the third element and a metal element, and the metal element and/or the third element and the first element form a fourth sub-layer; the surface layer coats part of the surface of the transition layer, and comprises a fast ion conductor which is used for forming a gradient heterojunction with the second layered structure. Thus, the battery using the positive electrode material realizes a cycle capacity retention rate at high voltage.
Description
Technical Field
The application relates to the technical field of lithium ion battery materials, in particular to a positive electrode material, a preparation method and application thereof.
Background
The lithium ion cathode materials in the current market are of various types, lithium cobalt oxide (LiCoO) 2 ) Is one of the positive electrode materials, liCoO 2 The lithium battery anode material has the advantages of good electrochemical performance, good energy storage property, mature production process and the like, and becomes the main stream of lithium battery anode materials in the current consumer electronics field.
However, liCoO is currently 2 When used as a positive electrode material, the material can generate structural phase change under high voltage, the crystal lattice is rapidly collapsed, and the irreversible oxygen loss phenomenon occurs, thereby exacerbating LiCoO 2 The structural deterioration and capacity fade during the battery cycling result in problems such as material structure being destroyed, the battery failing to achieve cycling capacity retention at high voltages, etc.
For this reason, it is necessary to provide a positive electrode material to solve the above problems.
Disclosure of Invention
The embodiment of the application provides a positive electrode material, a preparation method and application thereof, wherein a fast ion conductor in the positive electrode material can generate a gradient heterojunction with a transition layer, so that a phase interface is improved, the irreversible oxygen loss problem of the positive electrode material under high voltage is relieved, the positive electrode material has better high-voltage stability in a circulating process, the lithium ion battery can realize the circulating capacity retention rate under high voltage, and the performance of the lithium ion battery is improved.
In order to achieve the above purpose, the embodiment of the application adopts the following technical scheme:
in a first aspect, a positive electrode material is provided, comprising a body, a transition layer, and a surface layer; the body is a first layered structure, the first layered structure is composed of a first element, a second element and a third element, the first element forms a first sub-layer, the second element forms a second sub-layer, and the third element forms a third sub-layer; the transition layer is distributed along the direction deviating from the body, the transition layer at least comprises a second layered structure, the second layered structure is connected with the body, the second layered structure is composed of a first element, a second element and a third element, or the second layered structure is composed of the first element, the second element, the third element and a metal element, the metal element and/or the third element and the first element form a fourth sub-layer, the second element forms a fifth sub-layer, and the third element and/or the metal element form a sixth sub-layer; the arrangement of the fourth sub-layer is the same as that of the first sub-layer, the arrangement of the fifth sub-layer is the same as that of the second sub-layer, the arrangement of the sixth sub-layer is the same as that of the third sub-layer, the percentage content of the first element in the fourth sub-layer is smaller than that of the first element in the first sub-layer, and the percentage content of the third element in the sixth sub-layer is smaller than or equal to that of the third element in the third sub-layer; the surface layer coats part of the surface of the transition layer, and comprises a fast ion conductor which is used for forming a gradient heterojunction with the second layered structure.
The embodiment of the application provides a positive electrode material, wherein a disordered layered structure is at least built on the surface of a body in situ, the lithium content is gradually reduced from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the disordered layered structure, and as the fast ion conductor can react with the disordered layered structure and generate a gradient heterojunction, when a lithium ion battery is formed by a positive electrode plate, a negative electrode plate, an electrolyte, a diaphragm, related sealing materials and the like formed by the positive electrode material, the phase interface is improved, the side reaction between the body and the electrolyte under high voltage can be reduced, and the irreversible oxygen loss problem of the positive electrode material under high voltage is relieved; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the circulation capacity retention rate under high voltage can be realized by the lithium ion battery, and the performances such as the safety and the like of the lithium ion battery are improved.
In a possible implementation manner of the first aspect, a sum of the percentage content of the metal element and/or the third element in the fourth sub-layer and the percentage content of the first element is equal to the percentage content of the first element in the first sub-layer.
In this embodiment, the second layered structure is obtained by replacing the first element of the surface portion of the first layered structure with a third element of the metallic element and/or itself.
In a possible implementation manner of the first aspect, the transition layer further includes a spinel structure, where the spinel structure is distributed on a surface of the second layered structure facing away from the body direction and is connected to the second layered structure, and the spinel structure is composed of a first element, a second element, and a third element, or the spinel structure is composed of the first element, the second element, the third element, and a metal element; wherein the percentage content of the first element in the spinel structure is smaller than the percentage content of the first element in the second layered structure, and the percentage content of the third element in the spinel structure is smaller than or equal to the percentage content of the third element in the second layered structure; the fast ion conductor is used to form a gradient heterojunction with the spinel structure.
In the implementation mode, a disordered layered structure and a spinel structure are at least built in situ on the surface of a body of the positive electrode material, the lithium content is gradually reduced from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the spinel structure, so that the fast ion conductor can react with the spinel structure and generate a gradient heterojunction, when the positive electrode plate, the negative electrode plate, the electrolyte, the diaphragm, related sealing materials and the like formed by the positive electrode material form a lithium ion battery, the phase interface is improved, the side reaction between the body and the electrolyte under high voltage can be reduced, and the irreversible oxygen loss problem of the positive electrode material under high voltage is relieved; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the circulation capacity retention rate under high voltage can be realized by the lithium ion battery, and the performances such as the safety and the like of the lithium ion battery are improved.
In one possible implementation manner of the first aspect, the transition layer further includes a rock salt phase structure, the rock salt phase structure is distributed on a surface of the spinel structure facing away from the body direction and is connected with the spinel structure, the rock salt phase structure is composed of a second element, a third element and a metal element, wherein a percentage content of the third element in the rock salt phase structure is less than or equal to a percentage content of the third element in the spinel structure; the fast ion conductor is used for forming a gradient heterojunction with the rock salt phase structure.
In the implementation mode, a disordered layered structure, a spinel structure and a rock salt phase structure are at least built in situ on the surface of a body of the positive electrode material, the lithium content is gradually reduced from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the rock salt phase structure, so that the fast ion conductor can react with the rock salt phase structure and generate a gradient heterojunction, when the positive electrode plate, the negative electrode plate, the electrolyte, the diaphragm, related sealing materials and the like formed by the positive electrode material form a lithium ion battery, the phase interface is improved, the side reaction between the body and the electrolyte under high voltage can be reduced, and the irreversible oxygen loss problem of the positive electrode material under high voltage is relieved; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the circulation capacity retention rate under high voltage can be realized by the lithium ion battery, and the performances such as the safety and the like of the lithium ion battery are improved.
In one possible implementation manner of the first aspect, the positive electrode material includes: liCoO 2 Bulk, liCoO 2 The bulk is a layered structure having a Li layer (containing only Li element), an O layer (containing only O element), and a Co layer (containing only Co element); along the direction away from LiCoO 2 A transition layer distributed along the bulk direction, the transition layer at least comprises Li 1-m CoMO 2 Layer (M represents Li during substitution of metal M salt solution) + Lost content, migrating removed Li + By metal M ions and/or LiCoO 2 Part C of (2) O 3+ Substitution, 0<m<0.2, M is Li 1-m CoMO 2 The percentage content of the Li is in the range of 0% -0.05%) 1-m CoMO 2 Layer and LiCoO 2 The bodies are connected with each other, li 1- m CoMO 2 Has a fourth sub-layer (containing Li element, metal M element and/or Co element),An O layer (containing only O element) and a Co layer (containing Co element and/or M element), the fourth sub-layer being arranged in the same manner as the first sub-layer, li in the fourth sub-layer + Is less than Li in the first sub-layer + Is a percentage of (1); a fast ion conductor layer coating part of the surface of the transition layer, wherein the fast ion conductor in the fast ion conductor layer is used for being connected with Li 1-m CoMO 2 The layers form a gradient heterojunction.
In this implementation, liCoO 2 LiCoO of positive electrode material 2 Li of disordered lamellar structure is built on surface of body at least in situ 1-m CoMO 2 The lithium content of the layer is gradually reduced from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the disordered layered structure, and the fast ion conductor can be matched with Li 1-m CoMO 2 The layers react and form a gradient heterojunction, which improves the phase interface when used in a lithium ion battery, and can prevent electrolyte and LiCoO in the lithium ion battery 2 The body is in direct contact, thereby reducing LiCoO under high voltage 2 The side reaction between the body and the electrolyte effectively reduces the irreversible oxygen precipitation and relieves the irreversible oxygen loss phenomenon of the anode material under high voltage; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the structural stability and the circulation stability of the lithium ion battery are effectively improved under a high-voltage system, and the performance of the lithium ion battery is further improved.
In a possible implementation manner of the first aspect, the transition layer includes Li 1-m CoMO 2 Layer and Li 1-n Co 2 MO 4 Layer (n represents Li during substitution of metal M salt solution) + Lost content, migrating removed Li + By metal M ions and/or Li 1-m CoMO 2 Part C of (2) O 3+ Substitution, 0<n<0.25, M is Li 1-n Co 2 MO 4 The percentage content of the Li is in the range of 0% -0.05%) 1-n Co 2 MO 4 The layer is spinel structure, li 1-n Co 2 MO 4 Layer distribution in Li 1-m CoMO 2 Layer facing away from LiCoO 2 Surface in bulk direction and with Li 1-m CoMO 2 The layers are connected; the fast ion conductor in the fast ion conductor layer is used for connecting with Li 1-n Co 2 MO 4 Gradient heterojunction is formed between layers, li 1- n Co 2 MO 4 Li in layer + The content is less than Li 1-m CoMO 2 Li in layer + The content is as follows.
In this implementation, liCoO 2 Positive electrode material in LiCoO 2 Li of disordered lamellar structure built on surface of body in situ 1-m CoMO 2 Li of layered structure of layer and spinel 1-n Co 2 MO 4 The lithium content of the layer gradually decreases from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the spinel structure, and the fast ion conductor can be matched with Li 1-n Co 2 MO 4 The layers react and create a gradient heterojunction. When the electrolyte is applied to a lithium ion battery, the electrolyte and LiCoO in the lithium ion battery can be prevented due to the improvement of the phase interface 2 The body is in direct contact, thereby reducing LiCoO under high voltage 2 The side reaction between the body and the electrolyte effectively reduces the irreversible oxygen precipitation and relieves the irreversible oxygen loss phenomenon of the anode material under high voltage; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the structural stability and the circulation stability of the lithium ion battery are effectively improved under a high-voltage system, and the performance of the lithium ion battery is further improved.
In a possible implementation manner of the first aspect, the transition layer includes Li 1-m CoMO 2 Layer, li 1-n Co 2 MO 4 Layer and Co 1-z M z O layer (M is at least one of aluminum, titanium, cerium, nickel, manganese, magnesium, zirconium, niobium, silicon, ruthenium, iridium, tin, yttrium and lanthanum, 0)<z<0.2），Co 1-z M z The O layer is of a rock salt phase structure, co 1-z M z O layer is distributed in Li 1-n Co 2 MO 4 Layer facing away from LiCoO 2 Surface in bulk direction and with Li 1-n Co 2 MO 4 The layers are connected; the fast ion conductor in the fast ion conductor layer is used for being connected with Co 1-z M z Gradient heterojunction is formed between O layers, co 1-z M z Due to the absence of Li in the O layer + 。
In this implementation, liCoO 2 Positive electrode material in LiCoO 2 Li of disordered lamellar structure built on surface of body in situ 1-m CoMO 2 Li of layered structure of layer and spinel 1-n Co 2 MO 4 Co of lamellar and litho-salt phase structure 1-z M z The O layer gradually reduces the lithium content from inside to outside, and coats a layer of nano-scale fast ion conductor outside the rock salt phase structure, and the fast ion conductor can be combined with Co 1- z M z The O layer reacts and generates a gradient heterojunction, when the O layer is applied to a lithium ion battery, the phase interface is improved, and electrolyte and LiCoO in the lithium ion battery can be prevented 2 The body is in direct contact, thereby reducing LiCoO under high voltage 2 The side reaction between the body and the electrolyte effectively reduces the irreversible oxygen precipitation and relieves the irreversible oxygen loss phenomenon of the anode material under high voltage; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the structural stability and the circulation stability of the lithium ion battery are effectively improved under a high-voltage system, and the performance of the lithium ion battery is further improved.
In a second aspect, there is provided a lithium ion battery comprising a positive electrode sheet comprising a positive electrode material as in the first aspect or any possible implementation of the first aspect, a negative electrode sheet, an electrolyte and a separator.
The embodiment of the application provides a lithium ion battery which has better structural stability, cycle stability and the like under a high-voltage system and has good safety and the like.
In a third aspect, there is provided an electronic device comprising a lithium ion battery as in the second aspect or any possible implementation of the second aspect.
The embodiment of the application provides electronic equipment with good performance.
In a fourth aspect, a method for preparing a cathode material is provided, including the steps of:
forming a body of a first layered structure; the first layered structure consists of a first element, a second element and a third element, wherein the first element forms a first sub-layer, the second element forms a second sub-layer, and the third element forms a third sub-layer;
forming a transition layer in a direction away from the body of the first layered structure; the transition layer at least comprises a second layered structure, the second layered structure is connected with the body, the second layered structure is composed of a first element, a second element and a third element, or the second layered structure is composed of the first element, the second element, the third element and a metal element, the metal element and/or the third element and the first element form a fourth sub-layer, the second element forms a fifth sub-layer, and the third element and/or the metal element form a sixth sub-layer; the arrangement of the fourth sub-layer is the same as that of the first sub-layer, the arrangement of the fifth sub-layer is the same as that of the second sub-layer, the arrangement of the sixth sub-layer is the same as that of the third sub-layer, the percentage content of the first element in the fourth sub-layer is smaller than that of the first element in the first sub-layer, and the percentage content of the third element in the sixth sub-layer is smaller than or equal to that of the third element in the third sub-layer;
Forming a surface layer coating the transition layer on part of the surface of the transition layer; the surface layer comprises a fast ion conductor, and the fast ion conductor is used for forming a gradient heterojunction with the second layered structure.
The embodiment of the application provides a preparation method of a positive electrode material, which can be used for at least in-situ construction of a second layered structure of a disordered layered structure on the surface of a body, wherein the lithium content is gradually reduced from inside to outside, a layer of nano-scale fast ion conductor is formed outside the disordered layered structure, and the fast ion conductor can react with the disordered layered structure and generate a gradient heterojunction, so that when a lithium ion battery is formed by a positive electrode plate assembled by the positive electrode material, a negative electrode plate, an electrolyte, a diaphragm, related sealing materials and the like, a phase interface is improved, side reaction between the body and the electrolyte under high voltage can be reduced, and the irreversible oxygen loss problem of the positive electrode material under high voltage is relieved; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the circulation capacity retention rate under high voltage can be realized by the lithium ion battery, and the performances such as the safety and the like of the lithium ion battery are improved.
In a possible implementation manner of the fourth aspect, liCoO 2 The preparation method of the positive electrode material used as the body comprises the following steps: according to the lithium cobalt ratio of 1<Li/Co<10 preparing lithium salt and doped cobalt oxide precursor, uniformly mixing and grinding to obtain a mixture; drying the mixture, standing, and calcining the mixture after standing for one time to obtain LiCoO 2 Primary particles; liCoO is added with 2 Dissolving and uniformly mixing original particles in a first solution to obtain a first suspension; dissolving metal salt in the second solution, and stirring and mixing uniformly to obtain a metal salt solution; adding metal salt solution into the first suspension, stirring and mixing, dropwise adding gradually until all solvents are evaporated, calcining the obtained powder to obtain LiCoO with transition layer 2 Powder particles; liCoO with transition layer 2 After uniformly mixing the particles with the fast ion conductor slurry, drying and standing the powder to obtain mixture powder; after primary calcination of the mixture powder, liCoO with transition layer and coating layer is obtained in powder form 2 And a positive electrode material.
In this implementation, a transition layer having at least a disordered layered structure can be obtained.
In one possible implementation manner of the fourth aspect, the calcination temperature is set to be 200-600 ℃ and the calcination time is set to be 2-8 h.
In this implementation, liCoO with a disordered lamellar-spinel structure-rock salt phase transition layer is obtained 2 Powder particles.
In one possible implementation manner of the fourth aspect, the calcination temperature is set to be 200-400 ℃ and the calcination time is set to be 2-4 hours.
In this implementation, liCoO with disordered lamellar transition layers is obtained 2 Powder particles.
In one possible implementation manner of the fourth aspect, the calcination temperature is set to be 400-600 ℃ and the calcination time is set to be 4-8 h.
In this implementation, liCoO with disordered lamellar-spinel structure transition layer is obtained 2 Powder particles.
In a possible implementation manner of the fourth aspect, liCoO 2 The preparation method of the positive electrode material used as the body comprises the following steps: according to the lithium cobalt ratio of 1<Li/Co<10 preparing lithium salt and doped cobalt oxide precursor, uniformly mixing and grinding to obtain a mixture; drying the mixture, standing, and calcining the mixture after standing for one time to obtain LiCoO 2 Primary particles; dissolving metal salt in water, and uniformly stirring and mixing to obtain a metal salt solution; liCoO is added with 2 The original particles are dissolved in a metal salt solution at the temperature after the temperature is raised, and are subjected to quenching treatment to obtain the quenched LiCoO 2 Powder; quenching LiCoO 2 Washing the powder with a third solution, centrifuging, removing impurities, oven drying, and standing to obtain LiCoO with transition layer 2 Powder particles; liCoO with transition layer 2 After uniformly mixing the particles with the fast ion conductor slurry, drying and standing the powder to obtain mixture powder; after primary calcination of the mixture powder, liCoO with transition layer and coating layer is obtained in powder form 2 And a positive electrode material.
In this implementation, a transition layer having a disordered layered structure can be obtained.
The embodiment of the application provides a positive electrode material, the transition layer is built on the surface of a body in situ, and a nanoscale fast ion conductor is coated outside the transition layer, so that a gradient heterojunction can be formed between the fast ion conductor and the transition layer, when a lithium ion battery is formed by a positive electrode plate and a negative electrode plate which are formed by the positive electrode material, electrolyte, a diaphragm, related sealing materials and the like, the phase interface is improved, side reactions between the body and the electrolyte under high voltage are reduced, the irreversible oxygen loss phenomenon of the positive electrode material under high voltage is relieved, the positive electrode material has better high-voltage stability in the circulation process, the lithium ion battery can realize the circulation capacity retention rate under high voltage, and the safety and other performances of the lithium ion battery are improved.
Drawings
Fig. 1 is a schematic overall structure of an electronic device according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a split structure of the electronic device of FIG. 1;
fig. 3 is a schematic structural diagram of a lithium ion battery according to an embodiment of the present application;
fig. 4 is a sectional view of a lithium ion battery according to an embodiment of the present application;
FIG. 5 is an electron microscope image of a positive electrode material according to an embodiment of the present disclosure;
FIG. 6 is an electron microscope image of another positive electrode material according to an embodiment of the present application;
FIG. 7 is a scanning electron microscope image of a lithium cobaltate particle according to an embodiment of the present application;
fig. 8 is a process flow chart for preparing a positive electrode material according to an embodiment of the present application;
FIG. 9 is a flowchart of another process for preparing a positive electrode material according to an embodiment of the present disclosure;
fig. 10 is a flowchart of a preparation process of another positive electrode material according to an embodiment of the present application.
Reference numerals:
01-a mobile phone; 100-a display screen; 101-a middle frame; 102-a rear shell; 103-a circuit board assembly; 1031-a main circuit board; 1032-an electronic component; 104-a battery; 1041-lithium ion battery; 10-packaging film; 20-positive pole piece; 30-a negative electrode piece; 40-a membrane; 50-positive electrode lugs; 60-negative electrode tab.
Detailed Description
Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and variations thereof in the present specification and claims and in the accompanying drawings are intended to cover a non-exclusive inclusion.
In the description of the embodiments of the present application, the technical terms "first," "second," etc. are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
In the embodiment of the present application, the term "and/or" is merely an association relationship describing the association object, which means that three relationships may exist, for example, a and/or B may be represented: a exists alone, A and B exist together, and B exists alone.
In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.
In the embodiments herein, "plurality" means two or more (including two), and similarly, "plurality" means two or more (including two), and "multi-layer" means two or more (including two), unless explicitly specified and defined otherwise.
In the embodiments of the present application, the meaning of "at least one" refers to one or more than one.
In the embodiments of the present application, the azimuth or positional relationship indicated by the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of describing the embodiments of the present application and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific azimuth, be configured in a specific azimuth, etc., and are not to be construed as limiting the embodiments of the present application.
In the embodiments of the present application, the technical terms "mounted," "connected," "fixed," and the like are to be understood in a broad sense, for example, they may be fixed, detachable, or integrated; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between the two elements or interaction between the two elements. Those skilled in the art will understand the specific meaning of the terms described above in the embodiments of the present application according to the specific circumstances.
Some of the terms in the embodiments of the present application are explained below so that those skilled in the art can better understand them.
1. Lithium cobalt oxide
Lithium cobaltate, namely lithium cobalt oxide, is an inorganic compound of the formula LiCoO 2 . The cycling process of lithium cobaltate in a lithium ion battery refers to the charge and discharge process of the lithium cobaltate ion battery, namely the use process of the battery.
2. Fermi level (Fm)
Fm refers to the highest energy level of the material band filled with electrons at a temperature of absolute zero. Since the vacuum level is dependent on the surface conditions, it is easy to change, and this level is used as a reference level.
3. In situ synthesis method
In situ synthesis refers to a process in which the desired compound or material is synthesized directly in the starting material during a chemical reaction.
4. Fast ion conductor
Fast ionic conductors, also known as super ionic conductors, sometimes referred to as solid electrolytes, have an ionic conductivity (1 x 10) over a range of temperatures comparable to that of liquid electrolytes -6 S·cm -1 ) And low ion conductance activation energy (.ltoreq.0.40 eV).
5. Positive electrode plate
The positive electrode tab is an electrode in which electrons flow from an external circuit and the potential is high when the battery is discharged. The electrode may also be referred to as a cathode due to the reduction reaction.
6. Negative pole piece
The negative electrode plate is an electrode with low potential, from which electrons flow out from an external circuit when the battery is discharged. This electrode may also be referred to as an anode due to the oxidation reaction.
7. Circulation capacity
The cycle capacity refers to the electric quantity which can be released by the battery in one complete charge and discharge cycle, and the service life and stability of the battery are directly influenced by the size of the battery cycle capacity.
8. Cycle capacity retention rate
The cycle capacity retention rate refers to the capacity of a battery to retain a certain capacity after multiple charge and discharge. In general, higher cycle capacity retention means longer battery life and better stability.
The foregoing is a simple description of the terms involved in the embodiments of the present application, and will not be repeated herein.
In modern life, the functions of electronic devices such as notebook computers and mobile phones are increasingly important, and become one of the necessities of life of people.
The embodiment of the application provides electronic equipment, and the specific type of the electronic equipment is not limited. In some embodiments, the electronic device may include consumer electronics, home electronics, vehicle electronics, financial terminal electronics, communication electronics, and the like.
Among other things, consumer electronic terminal products may include notebook computers, tablet computers (pad), laptop computers (laptop), handheld computers, personal computers (personal computer, PC), cell phones (mobile phone), electronic readers, desktop displays, cellular phones, drones, personal digital assistants (personal digital assistant, PDA), smart wearable devices (e.g., smart bracelets, smart watches, headphones, etc.), ultra-mobile personal computers (ultra-mobile personal computer, UMPC), augmented reality (augmented reality, AR)/Virtual Reality (VR) devices, etc. internet of things (internet of things, IOT) devices, etc. Home electronics may include televisions, intelligent door locks, remote controls, refrigerators, charged home appliances (e.g., soymilk makers, floor sweeping robots, etc.), printers, projectors, etc. The vehicle-mounted electronic products may include a vehicle-mounted navigator, a vehicle-mounted high-density digital video disc (digital video disc, DVD), and the like. The financial terminal electronics may include automated teller machines (automated teller machine, ATM), self-service terminals, and the like. The communication electronics may include a server, memory, base station, etc. communication devices.
The embodiment of the application does not limit the specific form of the electronic device. For convenience of explanation, the electronic device is first exemplified as a mobile phone.
Referring to fig. 1 and fig. 2, fig. 1 is an overall schematic diagram of an electronic device suitable for some embodiments of the present application, and fig. 2 is a split schematic diagram of the electronic device shown in fig. 1.
The electronic devices shown in fig. 1 and 2 are each described by taking a tablet phone as an example. In other embodiments, the electronic device may be other types of mobile phones, such as a foldable mobile phone, etc.
In the examples of fig. 1 and 2, the electronic device may include a display screen 100, a center 101, a rear housing 102, a circuit board assembly 103, a battery 104, and the like. It will be appreciated that fig. 1 and 2 and the associated figures below only schematically illustrate some of the components of the electronic device, and that the actual shape, size, location, configuration, etc. of these components are not limited by fig. 1 and 2 and the figures below.
Specific structures of electronic devices suitable for the embodiments of the present application are further described below.
Referring to fig. 1 and fig. 2, taking an electronic device as an example of a mobile phone 01, the mobile phone 01 may include a display 100 and a middle frame 101, where the display 100 is located on one side of the middle frame 101.
In application, the display screen 100 may be used to display images, video, and the like.
The display screen 100 may be any one of a liquid crystal display screen (liquid crystal display, LCD), an organic light emitting diode (organic light emitting diode, OLED) display screen, a sub-millimeter light emitting diode (Mini light emitting diode, mini LED) display screen, a Micro light emitting diode (Micro light emitting diode, micro LED) display screen, and the like.
In the embodiment shown in fig. 1, the electronic device may have a rectangular flat plate shape. Of course, the shape of the electronic device may be any other shape, particularly, the shape is based on practical application.
As shown in fig. 2, the mobile phone 01 may further include a rear case 102, a circuit board assembly 103, a battery 104, and the like.
The rear case 102 may be disposed on a side of the middle frame 101 away from the display screen 100, and an internal accommodating space of the mobile phone 01 may be defined between the rear case 102 and the middle frame 101, where the internal accommodating space may accommodate the circuit board assembly 103, the battery 104, and other structures.
The circuit board assembly 103 described above may include a main circuit board 1031, electronic elements 1032, and the like. The main circuit board 1031 may be used for carrying the electronic element 1032 and performing signal interaction with the electronic element 1032. Fig. 2 illustrates an example of a circuit board assembly 103 including two electronic components 1032. Of course, the number of the electronic components 1032 may not be limited to two, and may be specific to practical applications.
In application, the main circuit board 1031 may include a printed circuit board (printed circuit boards, PCB), a flexible circuit board (flexible printed circuit, FPC), or the like.
In applications, electronic components 1032 may include, but are not limited to, chips, resistors, capacitors, inductors, potentiometers, electronic tubes, heat sinks, electromechanical components, connectors, semiconductor discrete devices, sensors, power supplies, switches, micro-motors, electronic transformers, relays, subscriber identity modules (subscriber identity module, SIM) cards, and the like.
The battery 104 described above may be used to provide power to structures within the cell phone 01, such as the display 100, the circuit board assembly 103, and the like.
In use, the surface of the middle frame 101 facing the rear case 102 may be provided with a battery mounting groove (not shown in fig. 2), the battery 104 may be mounted in the battery mounting groove, and the surface of the battery 104 may be provided with a battery cover (not shown in fig. 2) to protect the battery 104.
The current batteries 104 are typically chemical batteries, which can be categorized according to their operating properties: primary batteries (primary batteries), secondary batteries (rechargeable batteries), and lead-acid storage batteries. The primary battery can comprise a paste type zinc-manganese battery, a paper-like zinc-manganese battery, an alkaline zinc-manganese battery, a button type zinc-silver battery, a button type manganese-lithium battery, a zinc-air battery, a primary lithium-manganese battery and the like; the secondary battery may include a lithium ion battery, a cadmium-nickel battery, a hydrogen-nickel battery, a secondary alkaline zinc-manganese battery, and the like; the lead-acid battery may include an open lead-acid battery, a fully-closed lead-acid battery, and the like.
The secondary battery can reversibly convert chemical energy and electric energy, and is an ideal carrier for human use and energy storage. The lithium ion battery in the secondary battery is widely applied to various fields such as mobile phones, notebook computers, electric automobiles, energy storage power stations and the like due to the advantages of high energy density, high charge and discharge efficiency, small self-discharge, long service life, environmental friendliness and the like. The lithium ion battery provided in the embodiment of the present application is described in detail below with reference to fig. 3 and 4.
Fig. 3 is a schematic structural diagram of a lithium ion battery 1041 according to an embodiment of the present application.
As shown in fig. 3, the lithium ion battery 1041 may include a battery cell (not shown in fig. 1), an electrolyte (not shown in fig. 1), and a packaging film 10, the packaging film 10 being a case having a cavity, the battery cell and the electrolyte being both disposed in the packaging film 10. The battery cell is a storage portion of the lithium ion battery 1041. The electrolyte is filled in the lithium ion battery 1041, is an ion transport carrier of the lithium ion battery 1041, and plays a role in conducting ions between the positive electrode and the negative electrode of the lithium ion battery 1041.
Fig. 4 is a cross-sectional view of a lithium ion battery 1041 provided in an embodiment of the present application.
As shown in connection with fig. 3 and 4, the battery cell may include a positive electrode tab 20, a separator 40, and a negative electrode tab 30. When the battery cell adopts a lamination structure, the number of the positive electrode pole pieces 20 and the negative electrode pole pieces 30 can be multiple, and the positive electrode pole pieces 20 and the negative electrode pole pieces 30 can be light and thin flat plate structures. When the battery cell is formed through the lamination structure, the plurality of positive pole pieces 20 and the plurality of negative pole pieces 30 are separated through the diaphragm 40, and the positive pole pieces 20 and the negative pole pieces 30 are arranged alternately, namely, one negative pole piece 30 exists between two adjacent positive pole pieces 20, and one positive pole piece 20 exists between two adjacent negative pole pieces 30. The pole pieces are stacked together, adjacent positive pole pieces 20 and negative pole pieces 30 are separated by a diaphragm 40, and the diaphragm 40 separates the pole pieces in a z-shaped structure and is accommodated in the packaging film 10, so that a battery cell in a laminated state is obtained. For example, the separator 40 may be made of a porous polymer material, which can allow lithium ions in the electrolyte to pass through freely, but isolate the positive electrode plate from the negative electrode plate, so that electrons in the lithium ion battery 1041 cannot pass through freely.
In application, the positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer, wherein the positive electrode material layer can comprise a conductive agent, a solvent and a positive electrode material, and the positive electrode material layer is coated on the positive electrode current collector.
In application, the negative electrode plate comprises a negative electrode current collector and a negative electrode material layer, and the negative electrode material layer is coated on the surface of the negative electrode current collector. Illustratively, the negative current collector material of the lithium ion battery may be copper (Cu), the negative material layer may include a negative material, the negative material may be a silicon-based material, or the like.
In use, the negative and positive current collectors also have portions that are not coated with an active material layer, and these portions that are not provided with a connection tab. Referring to fig. 3 and 4 again, the positive electrode tab 20 is connected to the positive electrode tab 50, the negative electrode tab 30 is connected to the negative electrode tab 60, the number of the positive electrode tabs 50 is the same as the number of the positive electrode tabs 20, the number of the negative electrode tabs 60 is the same as the number of the negative electrode tabs 30, and the positive electrode tab 50 and the negative electrode tab 60 penetrate out from the longitudinal direction (H direction in fig. 3) of the packaging film 10.
Currently, liCoO 2 Is the main stream of positive electrode materials of lithium ion batteries in the consumer electronics field, and can be prepared by improving LiCoO 2 To increase its energy density. However, during the course of the study, it was found that as the voltage of the lithium ion battery increases, the performance degradation of the lithium ion battery is remarkable, mainly because: the working voltage is increased, liCoO 2 At high voltages, a structural phase change of O3 → monoclinic phase M → h1 → h2 → h3 → O1 may occur, resulting in rapid lattice collapse. I.e. LiCoO 2 In the process of converting the hexagonal system into the monoclinic system during charging, not only can larger volume change be generated, but also the phase change of the structure is irreversible, so that the problems of material structure damage, battery capacity attenuation and the like are caused; in addition, when the charging voltage is further increased, since the 3d energy band of Co and the 2p energy band of O overlap to a large extent, fm is positioned on the 2p energy band of O in the delithiated state, so that the lattice oxygen of the positive electrode material is oxidized, the material releases oxygen, namely, the irreversible oxygen losing phenomenon occurs under high voltage, and LiCoO is caused 2 Further collapse of the structure, more dramatic LiCoO 2 Structural deterioration and capacity fade during cycling to LiCoO 2 The thermal stability and the safety of the positive electrode material are correspondingly deteriorated, so that the performance, the service life and the like of the lithium ion battery are further influenced.
In view of this, the embodiment of the application provides a positive electrode material, at least an unordered layered structure is built on the surface of a body in situ, the lithium content is gradually reduced from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the unordered layered structure, because the fast ion conductor can react with the unordered layered structure and generate a gradient heterojunction, when the positive electrode plate, the negative electrode plate, the electrolyte, the diaphragm, related sealing materials and the like formed by the positive electrode material form a lithium ion battery, the phase interface is improved, the side reaction between the body and the electrolyte under high voltage can be reduced, and the irreversible oxygen loss problem of the positive electrode material under high voltage is relieved; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the circulation capacity retention rate under high voltage can be realized by the lithium ion battery, and the performances such as the safety and the like of the lithium ion battery are improved.
In practical application, lithium cobaltate is taken as an example, and the positive electrode material and the specific structure thereof provided in the embodiment of the application are described.
As shown in fig. 5 to 7, the positive electrode material provided in the embodiment of the present application includes: liCoO 2 Bulk, liCoO 2 The body is a layered structure having a first sub-layer (containing only Li element), a second sub-layer (containing only Li element)With O element) and a third sub-layer (containing only Co element). It should be noted that due to LiCoO 2 Each layer in the layered structure of the body contains only one element, so that the layered structure is an ordered layered structure; furthermore, liCoO 2 The body can also be written as Li 1 CoO 2 The ordered lamellar structure of the body can be a hexagonal lamellar structure.
Along the direction away from LiCoO 2 A transition layer distributed along the bulk direction, the transition layer at least comprises Li 1-m CoMO 2 Layer, li 1-m CoMO 2 Layer and LiCoO 2 The bodies are connected with each other, li 1-m CoMO 2 Having a fourth sublayer (containing Li element, metal M element and Co element, or containing Li element and Co element), a fifth sublayer (containing O element only) and a sixth sublayer (containing Co element and/or metal M element), the fourth sublayer being arranged identically to the first sublayer, the fifth sublayer being arranged identically to the second sublayer, the sixth sublayer being arranged identically to the third sublayer, li in the fourth sublayer + Is less than Li in the first sub-layer + Percentage content of Co in the sixth sublayer 3+ The percentage content of Co in the third sub-layer is less than or equal to 3+ Is a percentage of (1); wherein M represents Li in the process of replacing metal M salt solution + Lost content, migrating removed Li + By part of the M ions and/or LiCoO in the metal M salt solution 2 Part C of (2) O 3+ Substitution, 0<m<0.2M is at least one of aluminum (Al), titanium (Ti), cerium (Ce), nickel (Ni), manganese (Mn), magnesium (Mg), zirconium (Zr), niobium (Nb), silicon (Si), ruthenium (Ru), iridium (Ir), tin (Sn), yttrium (Y) and lanthanum (La), M is Li 1-m CoMO 2 The percentage content of the components is in the range of 0% -0.05%.
A fast ion conductor layer coating part of the surface of the transition layer, wherein the fast ion conductor in the fast ion conductor layer is used for being connected with Li 1- m CoMO 2 The layers form a gradient heterojunction.
M is derived from the treatment of LiCoO 2 Metal in the metal salt solution of (a). This is because: with structural changes, the Li layer is no longer regularIn the metal salt solution, metal ions and/or C O 3+ May migrate into the Li layer to occupy Li + The vacancies formed after the migration are converted to other structures. In addition, C O 3+ Not additionally introduced.
The method comprises the following steps: liCoO 2 The substitution reaction with a metal salt solution at a high temperature, at which time a part of LiCoO is present in the core 2 As a body, the reaction does not occur, and the ordered lamellar structure is still maintained; while the core LiCoO 2 Is present in the surface portion of Li + Loss of Li + The lost vacancies are formed by LiCoO 2 Part C of (2) O 3+ And/or partial metal M ion substitution in the metal salt solution, li thus obtained 1- m CoMO 2 The arrangement state of each layer in the layers is still similar to LiCoO 2 The arrangement state of each layer in the bulk is the same, only part of Li of the Li layer + Quilt C O 3+ And/or M ions replace, thus, li + The metal ion content of (2) is less than the metal ion content of the metal salt solution at the time of reaction. In addition, due to Li 1-m CoMO 2 Li in layer + Is replaced by Li + Is less than LiCoO 2 Li in the bulk + At the same time as the percentage content of Li lost + At least partially covered by C O 3+ Upon substitution, li 1-m CoMO 2 Layer C O 3+ Is less than or equal to LiCoO 2 Middle C O 3+ Is contained in the composition.
In the above process, lost Li + Is quilt C O 3+ Or M ion substitution, specifically according to the type of M element, if M ion can precede C O 3+ Filling the vacancy, then M ion is replaced if M ion cannot precede C O 3+ Filling the empty space, then is C O 3+ And (3) replacement.
In application, the specific type of the fast ion conductor is not limited, and exemplary fast ion conductors may include at least one of LiPON type fast ion conductor, garnet type fast ion conductor, perovskite type fast ion conductor, naSICON type fast ion conductor. The fast ion conductor has higher lithium content and can further react with the transition layer with lower lithium content during sintering.
Further, the LiPON type fast ion conductor may include LiPON or the like.
Further, the garnet-type fast ion conductor may include Li 7 La 3 Zr 2 O 12 (LLZO), and the like.
Further, the NaSICON-type fast ion conductor may include Li 1+x Al x Ti 2-x (PO4) 3 、Li 1+y Al y Ge 2-y (PO4) 3 And the like, wherein x is more than 0 and less than 2, and y is more than 0 and less than 2.
Illustratively, when x=0.3, the NaSICON-type fast ion conductor may be Li 1.3 Al 0.3 Ti 1.7 (PO4) 3 （LATP）。
Further, the perovskite type fast ion conductor may include Li 3p La 2/3-p TiO 3 And the like, wherein 0 < p < 2/3.
In application, the size of the fast ion conductor is not particularly limited, and the particle size of the fast ion conductor may range from 0.1nm to 100nm by way of example. Specifically, the particle diameter of the fast ion conductor may be 0.1nm, 1nm, 10nm, 50nm, 80nm, 100nm, or the like. As the fast ion conductor is used as a coating material, the smaller the particle size of the fast ion conductor is, the better the coating uniformity is, and the better the coating effect is.
It should be understood that the above surface layer covers part of the surface of the transition layer can be understood as: the surface layer is mainly formed by coating the surface of the transition layer in an island shape and is distributed on the surface of the transition layer in a scattered manner, so that the transition layer is coated unevenly and continuously, and the thickness of the surface layer is thinner.
In addition, it should be noted that the positive electrode material in the embodiment of the present application may include, but is not limited to, lithium cobaltate, and other materials, for example, materials having a layered structure, such as a ternary positive electrode material, a lithium-rich positive electrode material, and a sodium-electricity layered oxide positive electrode material, may all be reacted as a bulk to obtain the positive electrode material in the embodiment of the present application. The embodiment of the application is particularly suitable for the cell design of a high-voltage system.
Further, fig. 7 shows a scanning electron microscope image of lithium cobaltate particles. Wherein the small particles in fig. 7 are all coated fast ion conductors.
LiCoO provided by the embodiment of the application 2 Positive electrode material, liCoO 2 Li of disordered lamellar structure is built on surface of body at least in situ 1-m CoMO 2 The lithium content of the layer is gradually reduced from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the disordered layered structure, and the fast ion conductor can be matched with Li 1-m CoMO 2 The layers react and create a gradient heterojunction. When the electrolyte is applied to a lithium ion battery, the electrolyte and LiCoO in the lithium ion battery can be prevented due to the improvement of the phase interface 2 The body is in direct contact, thereby reducing LiCoO under high voltage 2 The side reaction between the body and the electrolyte effectively reduces the irreversible oxygen precipitation and relieves the irreversible oxygen loss phenomenon of the anode material under high voltage; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the structural stability and the circulation stability of the lithium ion battery are effectively improved under a high-voltage system, and the safety of the lithium ion battery is further improved.
Alternatively, as one achievable way, the transition layer comprises Li 1-m CoMO 2 Layer and Li 1-n Co 2 MO 4 Layer, li 1- n Co 2 MO 4 The layer is spinel structure, li 1-n Co 2 MO 4 Layer distribution in Li 1-m CoMO 2 Layer facing away from LiCoO 2 Surface in bulk direction and with Li 1-m CoMO 2 The layers are connected; the fast ion conductor in the fast ion conductor layer is used for connecting with Li 1-n Co 2 MO 4 Forming a gradient heterojunction between the layers; wherein n represents Li in the process of replacing metal M salt solution + Lost content, migrating removed Li + By part of the M ions and/or Li in the M salt solution 1-m CoMO 2 Part C of (2) O 3+ The replacement is carried out by a combination of the components,0<n<0.25, M is at least one of aluminum, titanium, cerium, nickel, manganese, magnesium, zirconium, niobium, silicon, ruthenium, iridium, tin, yttrium and lanthanum, M is Li 1-n Co 2 MO 4 The percentage content of the components is in the range of 0% -0.05%.
Li 1-n Co 2 MO 4 Li in layer + The content is less than Li 1-m CoMO 2 Li in layer + The content is as follows.
Li 1-n Co 2 MO 4 Layer C O 3+ Is less than or equal to Li 1-m CoMO 2 Layer C O 3+ Is contained in the composition.
It should be noted that m and n represent lithium ion contents lost during cycling due to structural transformation, and m may be smaller than n. Replacement of Li + The metal content of (2) is less than the metal content of the metal salt solution at the time of reaction.
In addition, if Li + All are separated and converted into Co 3 O 4 （CoO·Co 2 O 3 ) The rest is the same as Li 1-m CoMO 2 。
LiCoO provided by the embodiment of the application 2 Positive electrode material, liCoO 2 Li of disordered lamellar structure built on surface of body in situ 1-m CoMO 2 Li of layered structure of layer and spinel 1-n Co 2 MO 4 The lithium content of the layer gradually decreases from inside to outside, and a layer of nano-scale fast ion conductor is coated outside the spinel structure, and the fast ion conductor can be matched with Li 1-n Co 2 MO 4 The layers react and create a gradient heterojunction. When the electrolyte is applied to a lithium ion battery, the electrolyte and LiCoO in the lithium ion battery can be prevented due to the improvement of the phase interface 2 The body is in direct contact, thereby reducing LiCoO under high voltage 2 The side reaction between the body and the electrolyte effectively reduces the irreversible oxygen precipitation and relieves the irreversible oxygen loss phenomenon of the anode material under high voltage; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulating process, and the circulating under high voltage is realizedThe ring capacity retention rate is used for effectively improving the structural stability and the cyclic stability of the lithium ion battery under a high-voltage system, so that the safety of the lithium ion battery is improved.
Alternatively, as one realizable form, as shown in fig. 5-7, the transition layer comprises Li 1-m CoMO 2 Layer, li 1- n Co 2 MO 4 Layer and Co 1-z M z An O layer (wherein the metal M is at least one of aluminum, titanium, cerium, nickel, manganese, magnesium, zirconium, niobium, silicon, ruthenium, iridium, tin, yttrium, and lanthanum, 0) <z<0.2），Co 1-z M z The O layer is of a rock salt phase structure, co 1-z M z O layer is distributed in Li 1-n Co 2 MO 4 Layer facing away from LiCoO 2 Surface in bulk direction and with Li 1-n Co 2 MO 4 The layers are connected; the fast ion conductor in the fast ion conductor layer is used for being connected with Co 1-z M z And a gradient heterojunction is formed between the O layers.
Co 1-z M z Absence of Li in O layer + Thus Co 1-z M z Li in O layer + The content is the smallest, the rest is as in Li 1-m CoMO 2 。
Co 1-z M z C in O layer O 3+ Is less than or equal to Li 1-n Co 2 MO 4 Layer C O 3+ Is contained in the composition.
LiCoO provided by the embodiment of the application 2 Positive electrode material, liCoO 2 Li of disordered lamellar structure built on surface of body in situ 1-m CoMO 2 Li of layered structure of layer and spinel 1-n Co 2 MO 4 Co of lamellar and litho-salt phase structure 1-z M z The O layer gradually reduces the lithium content from inside to outside, and coats a layer of nano-scale fast ion conductor outside the rock salt phase structure, and the fast ion conductor can be combined with Co 1-z M z The O layer reacts and creates a gradient heterojunction. When the electrolyte is applied to a lithium ion battery, the electrolyte and LiCoO in the lithium ion battery can be prevented due to the improvement of the phase interface 2 The body is in direct contact, which reduces high voltageLower LiCoO 2 The side reaction between the body and the electrolyte effectively reduces the irreversible oxygen precipitation and relieves the irreversible oxygen loss phenomenon of the anode material under high voltage; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the structural stability and the circulation stability of the lithium ion battery are effectively improved under a high-voltage system, and the safety of the lithium ion battery is further improved.
Next, please refer to fig. 8 to fig. 10, a detailed description is given of a method for preparing the positive electrode material according to the embodiment of the present application.
As shown in fig. 8, the preparation method of the positive electrode material provided in the embodiment of the application includes the following steps:
s1, forming a body of the first layered structure.
The body of the first layered structure consists of a first element, a second element and a third element, wherein the first element forms a first sub-layer, the second element forms a second sub-layer, and the third element forms a third sub-layer.
S2, forming a transition layer in a direction away from the body of the first layered structure.
The transition layer at least comprises a second layered structure, the second layered structure is connected with the body of the first layered structure, the second layered structure is composed of a first element, a second element and a third element, or the second layered structure is composed of a first element, a second element, a third element and a metal element, the metal element and/or the third element and the first element form a fourth sub-layer, the second element forms a fifth sub-layer, and the third element and/or the metal element form a sixth sub-layer; the fourth sub-layer is identical to the first sub-layer in arrangement, the fifth sub-layer is identical to the second sub-layer in arrangement, the sixth sub-layer is identical to the third sub-layer in arrangement, the percentage content of the first element in the fourth sub-layer is smaller than the percentage content of the first element in the first sub-layer, and the percentage content of the third element in the sixth sub-layer is smaller than or equal to the percentage content of the third element in the third sub-layer.
The transition layer may also be referred to as a gradient layer.
It is understood that the transition layer comprising at least a second layered structure means that: the transition layer comprises only the second layered structure; or the transition layer comprises a second layered structure and a spinel structure, wherein the spinel structure is distributed on the surface of the second layered structure, which is far away from the body direction of the first layered structure, and is connected with the second layered structure, the fast ion conductor is used for forming a gradient heterojunction with the spinel structure, and the percentage content of the first element in the spinel structure is smaller than that of the first element in the second layered structure; or the transition layer comprises a second layered structure, a spinel structure and a rock salt phase structure, the rock salt phase structure is distributed on the surface of the spinel structure, which is far away from the body direction of the first layered structure, and is connected with the spinel structure, the percentage content of the first element in the rock salt phase structure is smaller than that of the first element in the spinel structure, and the fast ion conductor is used for forming a gradient heterojunction with the rock salt phase structure.
S3, forming a surface layer coating the transition layer on part of the surface of the transition layer.
The surface layer comprises a fast ion conductor, and the fast ion conductor is used for forming a gradient heterojunction with the second layered structure.
It should be noted that, in the embodiments of the present application, the first layered structure, the second layered structure, the spinel structure, the rock salt phase structure, and the like may refer to the above embodiments, and are not described herein again.
According to the preparation method of the positive electrode material, the second layered structure of the disordered layered structure is at least built in situ on the surface of the body of the ordered layered structure, the lithium content is gradually reduced from inside to outside, a layer of nano-scale fast ion conductor is formed outside the disordered layered structure, the fast ion conductor can react with the disordered layered structure and form a gradient heterojunction, so that when the positive electrode plate assembled by the positive electrode material, the negative electrode plate, the electrolyte, the diaphragm, related sealing materials and the like form a lithium ion battery, the phase interface is improved, the side reaction between the body and the electrolyte under high voltage can be reduced, and the irreversible oxygen loss problem of the positive electrode material under high voltage is relieved; meanwhile, the reversibility of the phase change of the positive electrode material under high voltage is improved, so that the positive electrode material has better high-voltage stability in the circulation process, the circulation capacity retention rate under high voltage is realized, the circulation capacity retention rate under high voltage can be realized by the lithium ion battery, the performances such as the safety and the like of the lithium ion battery are improved, and the lithium ion battery is simple and easy to realize.
As shown in fig. 9 and 10, liCoO provided for the embodiment of the present application 2 The method for preparing the positive electrode material as the body is described in detail.
The preparation method comprises the following steps:
1.LiCoO 2 preparation of the original particles (solid phase synthesis):
s11, preparing a lithium salt and a doped cobalt oxide precursor according to the ratio of lithium to cobalt being 1< Li/Co <10, uniformly mixing and grinding to obtain a mixture.
Wherein, can use the ball mill to carry out the ball-milling, ball mill rotational speed r1 is 300rpm < r1<1000rpm, and the ball-material ratio scope is 2:1~10:1. Further, the ball mill may be a planetary ball mill. By way of example, r1 may be 310rpm, 400rpm, 500rpm, 600rpm, 800rpm, 900rpm, or the like; the ball to material ratio may be 2:1, 3:1, 5:1, 6:1, 8:1, 10:1, etc.
In application, the lithium cobalt ratio Li/Co may be 1.05, 2, 3, 5, 8, or 9, etc. Further, li/Co may be 1.05.
The lithium salt may include anhydrous lithium hydroxide (LiOH), lithium carbonate (Li) 2 CO 3 ) Lithium nitrate (LiNO) 3 ) Lithium oxide (Li) 2 O), lithium acetate (LiCH) 3 COO), lithium chloride (LiCl) and lithium oxalate (C) 2 HLiO 4 ) At least one of the following.
The doped cobalt oxide precursor may include tricobalt tetraoxide (Co 3 O 4 ) Cobalt hydroxide (Co (OH) 2 ) Cobalt oxide (CoO), cobalt oxide (Co) 2 O 3 ) At least one of the following.
The doping element in the doped cobalt oxide precursor may comprise a combination of one or more of Al, ti, ce, ni, mn, mg, zr, nb, si, ru, ir, sn, Y, la, etc. The doping concentration of the doping element in the cobalt oxide precursor is not particularly limited, and the mass fraction of doping element doped in the cobalt oxide precursor may range from 0.7wt% to 1.1wt% by way of example. Specifically, the mass fraction of doping element doped in the cobalt oxide precursor may be in the range of 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%, 1.05wt%, 1.1wt%, or the like.
S12, drying the mixture, standing, and calcining the mixture after standing for one time to obtain LiCoO 2 Original particles.
The mixture can be dried in a blast oven with the temperature T1 of 50 ℃ and the temperature T1 of 130 ℃ and the standing time T1 of 2h and T1 and 10h. The temperature of the air-blast oven was set here to evaporate the solvent in the ball mill.
In application, the temperature T1 of the blast oven can be 60 ℃, 70 ℃, 80 ℃, 100 ℃, 110 ℃, 120 ℃ or the like.
The standing time t1 may be 3h, 4h, 5h, 7h, 8h, 9h, or the like.
Wherein the mixture after standing can be placed in a muffle furnace for calcination, the calcination temperature T2 ranges from 500 ℃ to < T2<1200 ℃, and the calcination time T2 ranges from 7h to T2 to 15h. Illustratively, the calcination temperature T2 may be 600 ℃, 700 ℃, 800 ℃, 900 ℃, 1000 ℃, 1100 ℃, or the like; the calcination time t2 may be 8h, 9h, 10h, 11h, 12h, 14h, or the like.
2. Preparation of the transition layer (solution or quench):
(1) First method-solution method:
s211. LiCoO 2 The primary particles are dissolved in the first solution and uniformly mixed to obtain a first suspension.
Wherein LiCoO can be added at 25 DEG C 2 The primary particles are dissolved in the first solution and uniformly mixed to obtain a first suspension.
In use, the first solution may include deionized water, a first organic solvent, and the like. Wherein the first organic solvent may comprise ethanol (C 2 H 5 OH), methanol (CH) 3 OH, isopropyl alcohol ]C 3 H 8 O), ethylene glycol (CH) 2 (OH)CH 2 (OH)), acetone (CH) 3 COCH 3 ) Dimethylformamide (C) 3 H 7 NO), and the like.
S212, dissolving the metal salt in the second solution, and stirring and mixing uniformly to obtain a metal salt solution.
Wherein the stirring temperature T3 is in the range of 25 ℃ < T3<60 ℃, and the stirring time T3 is in the range of 2h < T3<10h. Illustratively, the stirring temperature T3 may be 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, or the like; the stirring time t3 may be 3h, 4h, 5h, 7h, 8h, 9h, or the like.
In use, the metal salt may comprise a sulphate (M x (SO 4 ) y ) Chloride salt (M) x Cl y ) Nitrate (M) x (NO3) y ) At least one of soluble metal organic salts (M-R), and the like. Wherein M is a metal, and may specifically include at least one of Al, ti, ce, ni, mn, mg, zr, nb, si, ru, ir, sn, Y, la and the like; r is an organic molecular group, which may include CH 3 COO - Etc.
The second solution may include deionized water, a second organic solvent, and the like. Wherein the second organic solvent may comprise C 2 H 5 OH、CH 3 OH、C 3 H 8 O、CH 2 (OH)CH 2 (OH)、CH 3 COCH 3 、C 3 H 7 NO, etc.
S213, adding a metal salt solution into the first suspension, stirring and mixing the solution, dropwise adding the solution gradually until all the solvent is evaporated, and calcining the obtained powder to obtain LiCoO with a transition layer 2 Powder particles.
Wherein, the stirring temperature T4 during titration is in the range of 45 ℃ < T4<100 ℃, and the stirring time T4 during titration is in the range of 2h < T4<12h. Illustratively, the stirring temperature T4 at the time of dropping may be 50 ℃, 60 ℃, 70 ℃, 80 ℃, 85 ℃, 90 ℃, or the like; the stirring time t4 at the time of the dropping may be 3h, 4h, 5h, 7h, 9h, 11h, or the like.
Wherein the powder may be placed in a muffle furnace for calcination.
To obtain LiCoO having a transition layer with a disordered lamellar-spinel structure-halite phase structure 2 The powder particles are required to have a calcination temperature T5 of 200 DEG C<T5<600 ℃ and calcination time t5 of 2h<t5<8h. Illustratively, the calcination temperature T5 may be 250 ℃, 300 ℃, 350 ℃, 400 ℃, 450 ℃, 500 ℃, or the like; the calcination time t5 may be 3h, 4h, 5h, 6h, 7.5h, 7h, or the like.
To obtain LiCoO with disordered layered transition layer 2 The powder particles are required to have a calcination temperature T6 of 200 DEG C<T6<400 ℃ (lower temperature), calcination time t6 is 2h<t6<4h (shorter time). Illustratively, the calcination temperature T6 may be 250 ℃, 280 ℃, 300 ℃, 330 ℃, 380 ℃, 400 ℃, or the like; the calcination time t6 may be 2.4h, 2.7h, 3h, 3.2h, 3.5h, 3.8h, or the like.
LiCoO to obtain transition layer with disordered lamellar-spinel structure 2 The powder particles are required to have a calcination temperature T7 of 400 DEG C<T7<600 ℃ and calcination time t7 of 4h<t7<8h. Illustratively, the calcination temperature T7 may be 430 ℃, 450 ℃, 480 ℃, 520 ℃, 550 ℃, 580 ℃, or the like; the calcination time t7 may be 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, or the like.
The metal salt solution is slowly added into the first suspension in a titration mode, a thermodynamic driving force exists in the material during subsequent calcination, and based on the thermodynamic spontaneous process, the transition from an unstable structure to a more stable and/or more stable structure on the surface of the ordered lamellar structure can be realized, namely a transition layer is formed.
Based on the above, liCoO 2 In order to form a layered structure, when the metal salt solution with meta-acidity is subjected to displacement reaction at high temperature, the metal salt solution is reacted with LiCoO 2 Occurrence of Li + Exchange with H protons, which enter the material to abstract at least part of Li + And replace these Li + The position, and then during the subsequent sintering process, H protons burn off in the form of water, thereby capturing Li + A vacancy is present in the position of (2) at which the metal saltPart of the metal ions and/or LiCoO in the solution 2 Part Co of (B) 3+ Can fill the gaps, and LiCoO 2 A part of the core is not reacted as LiCoO 2 A body; in addition, when Co 3+ Filled with Li + The metal ions may also fill Co when empty 3+ Leaving voids, thereby, along a line facing away from LiCoO 2 The orientation of the body may transition from an ordered layered structure to an unordered layered structure.
Further, part of the metal ions in the metal salt solution and/or part of Co in the disordered layered structure 3+ Can be filled with Li + Vacancy, and when Co 3+ Filled with Li + The metal ions may also fill Co when empty 3+ Vacancies, thereby, along a direction away from LiCoO 2 The direction of the body can be sequentially changed from an ordered layered structure to an unordered layered structure and a spinel structure.
Further, part of the metal ions in the metal salt solution and/or part of Co in the spinel structure 3+ Can be filled with Li + Vacancy, and when Co 3+ Filled with Li + The metal ions may also fill Co when empty 3+ Vacancies, thereby, along a direction away from LiCoO 2 The direction of the bulk can be sequentially changed from an ordered lamellar structure to an unordered lamellar structure, a spinel structure and a rock salt phase structure, and Li + The content is reduced in turn until Li + And (5) complete removal.
(2) The second method (quenching method):
s221, dissolving metal salt in water, and stirring and mixing uniformly to obtain a metal salt solution.
Wherein the stirring temperature T8 is in the range of 25 ℃ < T8<60 ℃, and the stirring time T8 is in the range of 2h < T8<10h. By way of example, the stirring temperature T8 may be 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, or the like; the stirring time t8 may be 3h, 4h, 5h, 7h, 8h, 9h, or the like.
Wherein, the metal salt is dissolved in deionized water.
S222. LiCoO is added 2 The primary particles are dissolved in the metal salt solution at the temperature after the temperature is raisedIn the process, quenching treatment is carried out to obtain LiCoO after quenching 2 And (3) powder.
Wherein LiCoO can be used 2 The primary particles are placed in a muffle furnace to be heated, liCoO is added at high temperature 2 The primary particles are directly dissolved in the metal salt solution.
In application, the quenching time t9 ranges from 10s < t9<120s, and exemplary, the quenching time t9 may be 10s, 30s, 50s, 80s, 100s, 110s, etc.
S223, quenching the LiCoO 2 Washing the powder with a third solution, centrifuging, removing impurities, oven drying, and standing to obtain LiCoO with transition layer 2 Powder particles.
In use, the third solution may include deionized water, a second organic solvent, and the like. Wherein the second organic solvent may comprise C 2 H 5 OH、CH 3 OH、C 3 H 8 O、CH 2 (OH)CH 2 (OH)、CH 3 COCH 3 、C 3 H 7 NO, etc.
The centrifugal treatment can be carried out for 3-5 times, the rotation speed r2 of the centrifugal machine is 2000rpm < r2<7000rpm, and the centrifugal time t10 is 3min < t10<15min. Illustratively, the number of centrifugation may be 3, 4, 5, etc.; the centrifuge speed r2 may be 2500rpm, 3000rpm, 4000rpm, 5000rpm, 6000rpm, 6500rpm, or the like; the centrifugation time t10 may be 4min, 5min, 6min, 8min, 10min, 13min, or the like.
LiCoO after impurity removal 2 Can be placed in a blast oven with a temperature T9 of 50 DEG C<T9<130 ℃, and the standing time t11 ranges from 2h<t11<And 10h. Illustratively, the forced air oven temperature T9 may be 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, or the like; the standing time t11 may be 3h, 4h, 5h, 7h, 8h, 9h, or the like.
The impurities removed may include metal salt impurities, and thus, replace Li + Is necessarily less than the metal content of the metal salt solution.
At higher temperatures, liCoO 2 The surface has higherActivity, liCoO at this time 2 The body is immediately placed in a metal salt solution, liCoO 2 The high-temperature high-activity state of (2) is rapidly reacted with metal ions in the metal salt solution, the reaction time is rapid, and part of metal and/or LiCoO in the metal salt solution is quenched 2 Part Co of (B) 3+ Can be in LiCoO 2 Surface substitution of part of Li on the bulk + Thereby transitioning from an unstable structure to a stable structure at the surface of the body of the ordered layered structure, i.e. forming a transition layer. But generally along the direction away from LiCoO due to the too fast reaction 2 The orientation of the body may transition from a layered structure to a disordered layered structure.
Furthermore, liCoO 2 The content of the medium doping element is shown in LiCoO 2 The structure uses part of other metal elements to replace the content of Co, and the chemical formula is LiCo 1-p M p O 2 The other metal element may be a combination of one or more of Al, ti, ce, ni, mn, mg, zr, nb, si, ru, ir, sn, Y, la. The purpose of doping is to suppress LiCoO 2 Malignant structural phase transition at high voltages (e.g., voltages greater than 4.5V), enhancing LiCoO 2 Structural stability of the material at high voltages. And, the content of the doping element may be detected using Inductively Coupled Plasma (ICP).
3. Preparation of the coating layer:
s31 LiCoO with transition layer 2 And (3) uniformly mixing the particles with the fast ion conductor slurry, and drying and standing the powder to obtain the mixture powder.
Wherein, the powder can be put into a blast oven for drying and standing. The temperature T10 of the blast oven ranges from 50 ℃ to < T10<130 ℃, and the standing time T12 ranges from 2h to T12 to 10h. Illustratively, the forced air oven temperature T10 may be 60 ℃, 70 ℃, 80 ℃, 100 ℃, 110 ℃, 120 ℃, or the like; the standing time t12 may be 3h, 4h, 5h, 7h, 8h, 9h, or the like.
Wherein the proportion of the fast ion conductor powder is 0.1-6wt%, and the particle diameter D50 of the fast ion conductor powder is 0.01 μm < D50<1.1 μm. Illustratively, the fast ion conductor powder proportion may be 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, or 5wt%, etc.; the particle diameter D50 of the fast ion conductor may be 0.01 μm, 0.1 μm, 0.3 μm, 0.5 μm, 0.8 μm, 1.0 μm, or the like. The D50 is a particle size value corresponding to a cumulative distribution percentage of the fast ion conductor in the fast ion conductor slurry reaching 50%.
In application, liCoO with transition layer can be prepared by ball mill 2 The particles are mixed with the fast ion conductor paste. Further, the ball mill may be a planetary ball mill. The rotation speed r3 of the ball mill ranges from 300rpm<r3<1000rpm, and the ball-material ratio range is 2:1-10:1. Therefore, the powder can be ball-milled more finely, and the reaction is facilitated. Illustratively, the ball mill rotational speed r3 may be 310rpm, 400rpm, 500rpm, 600rpm, 800rpm, 900rpm, or the like; the ball to material ratio may be 2:1, 3:1, 5:1, 6:1, 8:1, 10:1, etc.
S32, calcining the mixture powder for one time to obtain LiCoO with transition layer and coating layer in powder form 2 And a positive electrode material.
Wherein the mixture powder can be calcined in a muffle furnace at a calcination temperature T11 ranging from 300 ℃ to < T9<1000 ℃ and a calcination time T13 ranging from 3h to T10 to 10h. By way of example, T11 may be 400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃, 900 ℃, or the like; the calcination time t13 may be 4h, 5h, 6h, 7h, 8h, 9h, or the like.
The preparation method of the positive electrode material provided by the embodiment of the application comprises the steps of adding a metal solution to enable the metal solution to be in contact with LiCoO 2 The bulk surface reacts with LiCoO 2 In-situ construction of transition layer with at least disordered lamellar structure from LiCoO 2 The lithium content from the body to the transition layer is gradually reduced, and the transition layer is coated with a layer of nano-scale fast ion conductor, the nano-scale fast ion conductor can be sintered with the transition layer at high temperature to generate a gradient heterojunction, and LiCoO under high voltage can be effectively inhibited 2 Side reactions with electrolyte, reduced irreversible oxygen evolution, and increased LiCoO at high voltage 2 Reversibility of structural phase transition, causing LiCoO 2 The structure stability in the circulation process under high voltage is better, the circulation capacity retention rate under high voltage is realized, and the cobalt is obviously improvedPerformance of lithium ion batteries with lithium acid as the positive electrode material.
The following examples illustrate the preparation methods and applications of the positive electrode materials in the examples of the present application and the positive electrode materials in the comparative examples.
The positive electrode material and the preparation method thereof are as follows:
example 1
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotating speed is 400rpm/min, ball milling time is 5h, and the mixture is rotated for 3min and then is left for 2min, so that the mixed precursor material is obtained.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a transition layer of an unordered layered structure, namely a spinel structure and a rock salt phase structure:
20g of LiCoO 2 Adding the original particles into the anhydrous C 2 H 5 Forming suspension in OH, adding 0.2g of niobium ethoxide solution (mass fraction of niobium ethoxide in the niobium ethoxide solution is 1 wt%) stirring in an oil bath at 80deg.C, and evaporating to dryness to obtain C 2 H 5 After the OH solvent, a evaporated powder was obtained.
Placing the evaporated powder in a muffle furnace, sintering at 400 deg.C for 4 hr at a temperature rise rate of 5 deg.C/min to obtain LiCoO with transition layer 2 And (3) powder.
3. Preparation of a fast ion conductor surface layer:
LiCoO2 powder and fast ionic conductor slurry LATP (coating amount of LATP is 1 wt%) are mixed, and a planetary ball mill is used for mixing after 3min and 2min under the conditions of a ball mass ratio of 4:1, a rotating speed of 400rpm/min and a mixing time of 4h, so that mixed powder is obtained.
And (3) drying the mixed powder in a drying oven to obtain a solvent, and placing the dried powder in a muffle furnace to be sintered at the sintering temperature of 800 ℃ for 8 hours and the temperature rise and fall rate of 5 ℃/min to obtain the anode material.
4. Preparation of a lithium ion battery:
and mixing the positive electrode material, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Example two
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotating speed is 400rpm/min, ball milling time is 5h, and the mixture is rotated for 3min and then is left for 2min, so that the mixed precursor material is obtained.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a transition layer of an unordered layered structure, namely a spinel structure and a rock salt phase structure:
20g of LiCoO 2 Adding the original particles into the anhydrous C 2 H 5 Forming suspension in OH, adding 0.2g of niobium ethoxide solution (mass fraction of niobium ethoxide in the niobium ethoxide solution is 1 wt%) stirring in an oil bath at 80deg.C, and evaporating to dryness to obtain C 2 H 5 After the OH solvent, a evaporated powder was obtained.
Placing the evaporated powder in a muffle furnace, and sintering at 400 deg.C for 4 hr at a temperature rise and fall rate of 5 deg.C/min to obtainObtaining LiCoO with transition layer 2 And (3) powder.
3. Preparation of a fast ion conductor surface layer:
LiCoO is added with 2 The powder was mixed with a rapid ion conductor paste LATP (coating amount of LATP was 2 wt%), and the mixture was stirred for 3 minutes and 2 minutes with a ball mass ratio of 4:1, a rotation speed of 400rpm/min, and a mixing time of 4 hours using a planetary ball mill to obtain a mixed powder.
And (3) drying the mixed powder in a drying oven to obtain a solvent, and placing the dried powder in a muffle furnace to be sintered at the sintering temperature of 800 ℃ for 8 hours and the temperature rise and fall rate of 5 ℃/min to obtain the anode material.
4. Preparation of a lithium ion battery:
and mixing the positive electrode material, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Example III
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotating speed is 400rpm/min, ball milling time is 5h, and the mixture is rotated for 3min and then is left for 2min, so that the mixed precursor material is obtained.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a transition layer of an unordered layered structure, namely a spinel structure and a rock salt phase structure:
20g of LiCoO 2 The original particles are added withoutWater C 2 H 5 Forming suspension in OH, adding 0.2g of niobium ethoxide solution (mass fraction of niobium ethoxide in the niobium ethoxide solution is 1 wt%) stirring in an oil bath at 80deg.C, and evaporating to dryness to obtain C 2 H 5 After the OH solvent, a evaporated powder was obtained.
Placing the evaporated powder in a muffle furnace, sintering at 400 deg.C for 4 hr at a temperature rise rate of 5 deg.C/min to obtain LiCoO with transition layer 2 And (3) powder.
3. Preparation of a fast ion conductor surface layer:
LiCoO is added with 2 Mixing the powder with a quick ion conductor slurry LLZO (the coating amount of the LLZO is 1 wt%) and using a planetary ball mill to mix at a ball mass ratio of 4:1, a rotation speed of 400rpm/min and a mixing time of 4h for 3min and stopping for 2min to obtain mixed powder.
And (3) drying the mixed powder in a drying oven to obtain a solvent, and placing the dried powder in a muffle furnace to be sintered at the sintering temperature of 800 ℃ for 8 hours and the temperature rise and fall rate of 5 ℃/min to obtain the anode material.
4. Preparation of a lithium ion battery:
and mixing the positive electrode material, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Example IV
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotation speed is 400rpm/min, ball milling time is 5h, and the reaction is carried out for 3min for 2min to obtain a mixed precursorA material.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a transition layer of a disordered layered structure:
20g of LiCoO 2 Adding the original particles into the anhydrous C 2 H 5 Forming suspension in OH, adding 0.2g of niobium ethoxide solution (mass fraction of niobium ethoxide in the niobium ethoxide solution is 1 wt%) stirring in an oil bath at 80deg.C, and evaporating to dryness to obtain C 2 H 5 After the OH solvent, a evaporated powder was obtained.
Placing the evaporated powder in a muffle furnace, sintering at 250deg.C for 2.5 hr at a temperature rise and fall rate of 5deg.C/min to obtain LiCoO with transition layer 2 And (3) powder.
3. Preparation of a fast ion conductor surface layer:
LiCoO2 powder and fast ionic conductor slurry LATP (coating amount of LATP is 1 wt%) are mixed, and a planetary ball mill is used for mixing after 3min and 2min under the conditions of a ball mass ratio of 4:1, a rotating speed of 400rpm/min and a mixing time of 4h, so that mixed powder is obtained.
And (3) drying the mixed powder in a drying oven to obtain a solvent, and placing the dried powder in a muffle furnace to be sintered at the sintering temperature of 800 ℃ for 8 hours and the temperature rise and fall rate of 5 ℃/min to obtain the anode material.
4. Preparation of a lithium ion battery:
and mixing the positive electrode material, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Example five
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotating speed is 400rpm/min, ball milling time is 5h, and the mixture is rotated for 3min and then is left for 2min, so that the mixed precursor material is obtained.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a transition layer of disordered layered structure-spinel structure:
20g of LiCoO 2 Adding the original particles into the anhydrous C 2 H 5 Forming suspension in OH, adding 0.2g of niobium ethoxide solution (mass fraction of niobium ethoxide in the niobium ethoxide solution is 1 wt%) stirring in an oil bath at 80deg.C, and evaporating to dryness to obtain C 2 H 5 After the OH solvent, a evaporated powder was obtained.
Placing the evaporated powder in a muffle furnace, sintering at 550deg.C for 7.5 hr at a temperature rise and fall rate of 5deg.C/min to obtain LiCoO with transition layer 2 And (3) powder.
3. Preparation of a fast ion conductor surface layer:
LiCoO2 powder and fast ionic conductor slurry LATP (coating amount of LATP is 1 wt%) are mixed, and a planetary ball mill is used for mixing after 3min and 2min under the conditions of a ball mass ratio of 4:1, a rotating speed of 400rpm/min and a mixing time of 4h, so that mixed powder is obtained.
And (3) drying the mixed powder in a drying oven to obtain a solvent, and placing the dried powder in a muffle furnace to be sintered at the sintering temperature of 800 ℃ for 8 hours and the temperature rise and fall rate of 5 ℃/min to obtain the anode material.
4. Preparation of a lithium ion battery:
and mixing the positive electrode material, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Example six
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotating speed is 400rpm/min, ball milling time is 5h, and the mixture is rotated for 3min and then is left for 2min, so that the mixed precursor material is obtained.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a transition layer of a disordered layered structure:
20g of LiCoO 2 Dissolving the original particles in 0.2g of niobium ethoxide solution (the mass fraction of niobium ethoxide in the niobium ethoxide solution is 1 wt%) at high temperature, quenching, cleaning, centrifuging, removing metal salt impurities, oven drying, and standing to obtain LiCoO with transition layer 2 And (3) powder.
3. Preparation of a fast ion conductor surface layer:
LiCoO2 powder and fast ionic conductor slurry LATP (coating amount of LATP is 1 wt%) are mixed, and a planetary ball mill is used for mixing after 3min and 2min under the conditions of a ball mass ratio of 4:1, a rotating speed of 400rpm/min and a mixing time of 4h, so that mixed powder is obtained.
And (3) drying the mixed powder in a drying oven to obtain a solvent, and placing the dried powder in a muffle furnace to be sintered at the sintering temperature of 800 ℃ for 8 hours and the temperature rise and fall rate of 5 ℃/min to obtain the anode material.
4. Preparation of a lithium ion battery:
and mixing the positive electrode material, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Second, positive electrode material of comparative example and preparation method thereof example:
comparative example one
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotating speed is 400rpm/min, ball milling time is 5h, and the mixture is rotated for 3min and then is left for 2min, so that the mixed precursor material is obtained.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 And a positive electrode material.
2. Preparation of a lithium ion battery:
LiCoO is added with 2 And mixing the positive electrode material, the conductive carbon black and the PVDF according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Comparative example two
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 Al with the mass fraction of 0.9wt% is mixed uniformly, and planetary ball milling is usedThe machine is characterized in that the ball-material ratio is 5:1, and the dispersing agent is ethanol (C 2 H 5 OH), ball milling rotating speed is 400rpm/min, ball milling time is 5h, and the mixture is rotated for 3min and then is left for 2min, so that the mixed precursor material is obtained.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a transition layer of a lamellar structure-disordered lamellar structure-spinel structure-rock salt phase structure:
20g of LiCoO 2 Adding the original particles into the anhydrous C 2 H 5 Forming suspension in OH, adding 0.2g of niobium ethoxide solution (mass fraction of niobium ethoxide in the niobium ethoxide solution is 1 wt%) stirring in an oil bath at 80deg.C, and evaporating to dryness to obtain C 2 H 5 After the OH solvent, a evaporated powder was obtained.
And (3) placing the evaporated powder in a muffle furnace, and sintering at the sintering temperature of 400 ℃ for 4 hours and the temperature rising and dropping speed of 5 ℃/min to obtain the positive electrode material with the transition layer.
3. Preparation of a lithium ion battery:
and mixing the anode material with the transition layer, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain anode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
Comparative example three
1.LiCoO 2 Preparation of the original particles:
7.55g of LiOH and 16.40g of Co are added according to the stoichiometric ratio 3 O 4 （Co 3 O 4 After being evenly mixed with 0.9 weight percent of Al, the mixture is mixed with a planetary ball mill, wherein the ball-material ratio is 5:1, and the dispersing agent is ethanol (C) 2 H 5 OH), ball milling rotation speed of 400rpm/min and ball milling time of 5h, rotating for 3min and then resting for 2mAnd in, obtaining the mixed precursor material.
The precursor material is placed in a muffle furnace to be sintered at the sintering temperature of 1000 ℃ for 12 hours and the temperature rise and fall rate of 5 ℃/min to obtain 20g LiCoO 2 Original particles.
2. Preparation of a fast ion conductor surface layer:
20g of LiCoO 2 Mixing the original particles with fast ion conductor slurry LATP (the coating amount of the LATP is 1 wt%) and using a planetary ball mill to mix at a ball mass ratio of 4:1, a rotation speed of 400rpm/min and a mixing time of 4h for 3min and stopping for 2min to obtain mixed powder.
And (3) drying the mixed powder in a drying oven to obtain a solvent, and placing the dried powder in a muffle furnace to be sintered at the sintering temperature of 800 ℃ for 8 hours and the temperature rise and fall rate of 5 ℃/min to obtain the anode material.
3. Preparation of a lithium ion battery:
and mixing the positive electrode material, conductive carbon black and polyvinylidene fluoride (PVDF) according to the mass ratio of 92:3:5 to obtain positive electrode slurry.
And (3) coating the anode slurry on the surface of an aluminum foil, drying and cutting into small wafers with the diameter of 12mm to obtain the anode plate.
The positive electrode sheet, a metallic lithium sheet having a diameter of 14mm, a separator having a diameter of 16mm, and 100uL of electrolyte were assembled into an R2032 button cell.
The R2032 coin cells prepared in examples 1 to 6 and comparative examples 1 to 3 were placed on a new wiring tester to test the electrochemical properties of the R2032 coin cells.
The electrochemical performance test conditions were as follows:
The testing temperature is set to 45 ℃, and the assembled R2032 button cell is placed on a charge-discharge tester for testing.
The cycle conditions of the charge and discharge tester are as follows: first week: constant current and constant voltage charge to 4.65V with current density of 0.2C, cut-off current of 0.025C, and constant current discharge to 3V with 0.2C. At the following weeks 2 to 51: charging to 4.6V with constant current and constant voltage of 0.5C, and discharging to 3V with constant current of 0.5C when discharging with cutoff current of 0.025C. Note that, 1 c=274 mA/g.
The first coulombic efficiency and 50-week capacity retention of the lithium ion batteries of comparative example 1, example 4, example 5 were obtained through the above-described tests, as shown in table 1 below.
TABLE 1
As can be seen from table 1, example 4 and example 5 are respectively compared with comparative example 1, since the positive electrode material of the lithium ion battery of the present application has a transition layer, whereas the positive electrode material of the lithium ion battery of comparative example 1 has no transition layer, the first coulombic efficiency and the 50-week capacity retention rate of the lithium ion battery of the present application are both higher, and the performance of the lithium ion battery is better.
Further, example 2 only increased the coating amount of LATP compared to example 1, and the higher the coating amount of LATP, the higher both the first coulombic efficiency and the 50-week capacity retention rate of the lithium ion battery.
Example 3 the first coulombic efficiency and 50 week capacity retention of the lithium ion battery of example 3 were both higher, substituting LATP for LLZO in example 1.
The higher the coulombic efficiency, the smaller the capacity lost in each cycle of the lithium ion battery, and the longer the life of the lithium ion battery.
It should be understood that the foregoing is only intended to assist those skilled in the art in better understanding the embodiments of the present application and is not intended to limit the scope of the embodiments of the present application. From the above examples given, it will be apparent to those skilled in the art that various equivalent modifications or variations may be made, for example, that certain steps may be unnecessary in various embodiments of the method, that certain steps may be newly added, etc.; or a combination of any two/more of the above embodiments. Such modifications, variations, or combinations are also within the scope of embodiments of the present application.
It should also be understood that the foregoing description of embodiments of the present application focuses on highlighting differences between the various embodiments and that the same or similar elements not mentioned may be referred to each other and are not described in detail herein for brevity.
It should be further understood that the sequence numbers of the above processes do not mean the order of execution, and the order of execution of the processes should be determined by the functions and the internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.
It should also be understood that the manner, condition, class and division of the embodiments in the embodiments of the present application are for convenience of description only and should not be construed as being particularly limited, and the various manners, classes, conditions and features of the embodiments may be combined without contradiction.
It is also to be understood that in the various embodiments of the application, terms and/or descriptions of the various embodiments are consistent and may be referenced to one another in the absence of a particular explanation or logic conflict, and that the features of the various embodiments may be combined to form new embodiments in accordance with their inherent logic relationships.
Finally, it should be noted that: the foregoing is merely a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (18)
1. A positive electrode material, characterized by comprising: the device comprises a body, a transition layer and a surface layer;
the body is of a first layered structure, the first layered structure is composed of a first element, a second element and a third element, the first element forms a first sub-layer, the second element forms a second sub-layer, and the third element forms a third sub-layer;
The transition layer is distributed along the direction deviating from the body, the transition layer at least comprises a second layered structure, the second layered structure is connected with the body, the second layered structure is composed of the first element, the second element and the third element, or the second layered structure is composed of the first element, the second element, the third element and a metal element, the metal element and/or the third element and the first element form a fourth sub-layer, the second element forms a fifth sub-layer, and the third element and/or the metal element form a sixth sub-layer; the arrangement of the fourth sub-layer and the first sub-layer is the same, the arrangement of the fifth sub-layer and the second sub-layer is the same, the arrangement of the sixth sub-layer and the third sub-layer is the same, the percentage content of the first element in the fourth sub-layer is smaller than the percentage content of the first element in the first sub-layer, and the percentage content of the third element in the sixth sub-layer is smaller than or equal to the percentage content of the third element in the third sub-layer;
the surface layer coats part of the surface of the transition layer, and comprises a fast ion conductor which is used for forming a gradient heterojunction with the second layered structure.
2. The positive electrode material according to claim 1, wherein a sum of the percentage content of the metal element and/or the third element in the fourth sub-layer and the percentage content of the first element is equal to the percentage content of the first element in the first sub-layer.
3. The positive electrode material according to claim 2, wherein the transition layer further comprises a spinel structure which is distributed on a surface of the second layered structure facing away from the bulk direction and is connected to the second layered structure, the spinel structure being composed of the first element, the second element, and the third element, or the spinel structure being composed of the first element, the second element, the third element, and a metal element; wherein the percentage content of the first element in the spinel structure is less than the percentage content of the first element in the second layered structure;
the fast ion conductor is used for forming a gradient heterojunction with the spinel structure.
4. The positive electrode material according to claim 3, wherein the transition layer further comprises a rock salt phase structure which is distributed on a surface of the spinel structure facing away from the bulk direction and is connected to the spinel structure, the rock salt phase structure being composed of the second element, the third element, and a metal element;
The fast ion conductor is used for forming a gradient heterojunction with the rock salt phase structure.
5. The positive electrode material according to any one of claims 2 to 4, wherein the body is a lithium cobalt oxide body having a chemical formula of LiCoO 2 ；
At the LiCoO 2 The first sub-layer contains Li element, the second sub-layer contains O element, and the third sub-layer contains Co element.
6. The positive electrode material according to any one of claims 2 to 4, wherein the chemical formula of the second layered structure is Li 1-m CoMO 2 Wherein m represents Li + Content of lost, li lost + By metal ions and/or C O 3+ Substitution, 0<m<0.2, M is at least one of aluminum, titanium, cerium, nickel, manganese, magnesium, zirconium, niobium, silicon, ruthenium, iridium, tin, yttrium and lanthanum, M is Li 1-m CoMO 2 The percentage content range of the components is 0% -0.05%;
at the Li 1-m CoMO 2 The fourth sub-layer contains Li element and M element and/or Co element, the fifth sub-layer contains O element, and the sixth sub-layer contains Co element and/or M element.
7. The positive electrode material according to claim 3 or 4, wherein the spinel structure has a chemical formula of Li 1- n Co 2 MO 4 Wherein n represents Li + Content of lost, li lost + By metal ions and/or C O 3+ Substitution, 0<n<0.25, M is at least one of aluminum, titanium, cerium, nickel, manganese, magnesium, zirconium, niobium, silicon, ruthenium, iridium, tin, yttrium and lanthanum, M is Li 1-n Co 2 MO 4 The percentage content range of the components is 0% -0.05%;
at the Li 1-n Co 2 MO 4 The first element is Li, the second element is O, and the third element is Co.
8. The positive electrode material according to claim 4, wherein the rock salt phase structure has a chemical formula of Co 1-z M z O, wherein M is at least one of aluminum, titanium, cerium, nickel, manganese, magnesium, zirconium, niobium, silicon, ruthenium, iridium, tin, yttrium and lanthanum, 0<z<0.2；
At the Co 1-z M z In O, the second element is O element, and the third element is Co element.
9. The positive electrode material according to any one of claims 1 to 4, wherein the fast ion conductor has a particle diameter ranging from 0.1nm to 100nm.
10. The positive electrode material according to any one of claims 1 to 4, wherein the fast ion conductor comprises at least one of a LiPON-type fast ion conductor, a garnet-type fast ion conductor, a perovskite-type fast ion conductor, a NaSICON-type fast ion conductor.
11. A lithium ion battery comprising a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator, wherein the positive electrode sheet comprises the positive electrode material according to any one of claims 1 to 10.
12. An electronic device comprising the lithium-ion battery of claim 11.
13. A method for preparing a positive electrode material, comprising:
forming a body of a first layered structure; the first layered structure consists of a first element, a second element and a third element, wherein the first element forms a first sub-layer, the second element forms a second sub-layer, and the third element forms a third sub-layer;
forming a transition layer in a direction away from the body of the first layered structure; the transition layer at least comprises a second layered structure, the second layered structure is connected with the body, the second layered structure is composed of the first element, the second element and the third element, or the second layered structure is composed of the first element, the second element, the third element and a metal element, the metal element and/or the third element and the first element form a fourth sub-layer, the second element forms a fifth sub-layer, and the third element and/or the metal element form a sixth sub-layer; the arrangement of the fourth sub-layer and the first sub-layer is the same, the arrangement of the fifth sub-layer and the second sub-layer is the same, the arrangement of the sixth sub-layer and the third sub-layer is the same, the percentage content of the first element in the fourth sub-layer is smaller than the percentage content of the first element in the first sub-layer, and the percentage content of the third element in the sixth sub-layer is smaller than or equal to the percentage content of the third element in the third sub-layer;
Forming a surface layer coating the transition layer on part of the surface of the transition layer; the surface layer comprises a fast ion conductor, and the fast ion conductor is used for forming a gradient heterojunction with the second layered structure.
14. The method of producing a positive electrode material according to claim 13, wherein the body of the first layered structure is a lithium cobalt oxide body;
the body forming the first layered structure includes:
preparing lithium salt and doped cobalt oxide precursor according to the ratio of lithium to cobalt, uniformly mixing and grinding to obtain a mixture;
and (3) drying the mixture, standing, and calcining the mixture after standing for the first time to obtain the lithium cobaltate original particles.
15. The method of claim 14, wherein forming the transition layer in a direction away from the body of the first layered structure comprises:
dissolving and uniformly mixing the lithium cobaltate primary particles in a first solution to obtain a first suspension;
dissolving metal salt in the second solution, and stirring and mixing uniformly to obtain a metal salt solution;
and adding the metal salt solution into the first suspension, stirring, mixing and gradually dropwise adding until all the solvent is evaporated to dryness, and calcining the obtained powder to obtain lithium cobalt oxide powder particles with a transition layer.
16. The method for preparing a positive electrode material according to claim 15, wherein the calcination temperature is in the range of 200 ℃ to 600 ℃ and the calcination time is in the range of 2 hours to 8 hours;
or the calcination temperature ranges from 200 ℃ to 400 ℃ and the calcination time ranges from 2 hours to 4 hours;
or the calcination temperature ranges from 400 ℃ to 600 ℃ and the calcination time ranges from 4 hours to 8 hours.
17. The method of claim 14, wherein forming the transition layer in a direction away from the body of the first layered structure comprises:
dissolving metal salt in water, and uniformly stirring and mixing to obtain a metal salt solution;
dissolving the lithium cobaltate primary particles in a metal salt solution at the temperature after heating, and carrying out quenching treatment to obtain quenched lithium cobaltate powder;
and cleaning and centrifuging the quenched lithium cobalt oxide powder by using a third solution, removing impurities, drying and standing to obtain lithium cobalt oxide powder particles with a transition layer.
18. The method of producing a positive electrode material according to any one of claims 15 to 17, wherein the forming of the surface layer covering the transition layer on a part of the surface of the transition layer comprises:
uniformly mixing the lithium cobaltate powder particles with the transition layer with the fast ion conductor slurry, and drying and standing the powder to obtain mixture powder;
And calcining the mixture powder to obtain the positive electrode material.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11310416A (en) * | 1998-04-27 | 1999-11-09 | Carnegie Mellon Univ | Cathodic substance of lithium ion secondary battery |
| JP2006164758A (en) * | 2004-12-07 | 2006-06-22 | Seimi Chem Co Ltd | Positive electrode material for lithium secondary battery |
| CN102214819A (en) * | 2010-04-09 | 2011-10-12 | 北京化工大学 | Method for manufacturing cobalt nickel lithium manganate oxide as gradient anode active material of lithium ion battery |
| CN111799468A (en) * | 2020-08-13 | 2020-10-20 | 中南大学 | Lithium ion battery anode material jointly modified by ionic conductor and heterostructure, preparation method and application |
| US20210135191A1 (en) * | 2019-11-05 | 2021-05-06 | Seiko Epson Corporation | Positive Electrode Active Material Composite Body |
| CN113097481A (en) * | 2020-01-08 | 2021-07-09 | 中国科学院物理研究所 | Lithium ion battery anode material with core-shell structure and lithium ion battery |
| CN113921773A (en) * | 2020-07-08 | 2022-01-11 | 中国科学院物理研究所 | Surface-coated modified lithium ion battery positive electrode material and preparation method and application thereof |
| CN115732675A (en) * | 2021-08-25 | 2023-03-03 | 华为技术有限公司 | Lithium ion battery anode material and preparation method thereof, lithium ion battery and electronic equipment |
| CN115763753A (en) * | 2022-11-29 | 2023-03-07 | 宁波容百新能源科技股份有限公司 | Modified lithium-rich cathode material and preparation method thereof |
| CN116435477A (en) * | 2023-03-29 | 2023-07-14 | 珠海冠宇电池股份有限公司 | Positive electrode material, positive electrode sheet and battery |
| CN117543018A (en) * | 2023-11-17 | 2024-02-09 | 天津巴莫科技有限责任公司 | Positive electrode material, preparation method thereof, positive electrode plate, lithium ion battery and electric equipment |
-
2024
- 2024-03-01 CN CN202410233691.3A patent/CN117810454A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11310416A (en) * | 1998-04-27 | 1999-11-09 | Carnegie Mellon Univ | Cathodic substance of lithium ion secondary battery |
| JP2006164758A (en) * | 2004-12-07 | 2006-06-22 | Seimi Chem Co Ltd | Positive electrode material for lithium secondary battery |
| CN102214819A (en) * | 2010-04-09 | 2011-10-12 | 北京化工大学 | Method for manufacturing cobalt nickel lithium manganate oxide as gradient anode active material of lithium ion battery |
| US20210135191A1 (en) * | 2019-11-05 | 2021-05-06 | Seiko Epson Corporation | Positive Electrode Active Material Composite Body |
| CN113097481A (en) * | 2020-01-08 | 2021-07-09 | 中国科学院物理研究所 | Lithium ion battery anode material with core-shell structure and lithium ion battery |
| CN113921773A (en) * | 2020-07-08 | 2022-01-11 | 中国科学院物理研究所 | Surface-coated modified lithium ion battery positive electrode material and preparation method and application thereof |
| CN111799468A (en) * | 2020-08-13 | 2020-10-20 | 中南大学 | Lithium ion battery anode material jointly modified by ionic conductor and heterostructure, preparation method and application |
| CN115732675A (en) * | 2021-08-25 | 2023-03-03 | 华为技术有限公司 | Lithium ion battery anode material and preparation method thereof, lithium ion battery and electronic equipment |
| CN115763753A (en) * | 2022-11-29 | 2023-03-07 | 宁波容百新能源科技股份有限公司 | Modified lithium-rich cathode material and preparation method thereof |
| CN116435477A (en) * | 2023-03-29 | 2023-07-14 | 珠海冠宇电池股份有限公司 | Positive electrode material, positive electrode sheet and battery |
| CN117543018A (en) * | 2023-11-17 | 2024-02-09 | 天津巴莫科技有限责任公司 | Positive electrode material, preparation method thereof, positive electrode plate, lithium ion battery and electric equipment |
Non-Patent Citations (2)
| Title |
|---|
| 张联齐;肖成伟;杨瑞娟;: "有序/无序岩盐结构的Li_(1+x)M_(1-x)O_2锂离子电池正极材料", 化学进展, no. 1, 24 March 2011 (2011-03-24) * |
| 黄友元, 周恒辉, 陈继涛, 苏光耀, 高德淑: "层状嵌锂多元过渡金属氧化物的研究", 化学进展, no. 03, 24 May 2005 (2005-05-24) * |
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